I just got a steal on ebay, a drag specialties mustang tank for under 100 shipped. I've been debating about my plumbing options and am curious how others have done it. At this point I'm leaning toward a petcock in all 3 ports. The 3/8" being the primary line (one of pandemoniums hose style) and the two 1/4 being pet cocked turned off in normal riding and plumbed to a T and then that T plumbed in after the 3/8" NPT petcock. That was it should be able to act as an effective reserve. If the 3/8" upper runs out I can open the two lower 1/4" and they would feed in. The only downfall to this method is the sheer cost of 3 petcocks.